Scientific Note Cardamine impatiens and Sibara virginica (Brassicaceae) in West Virginia
Scientific Note Cardamine impatiens and Sibara virginica (Brassicaceae) in West Virginia
Scientific Note Cardamine impatiens and Sibara virginica (Brassicaceae) in West Virginia
ABSTRACT Over a decade of study reveals that the vascular flora of the James River Gorge watersheds between Snowden and Glasgow, Virginia, including portions of the James River Face Wilderness, and portions of Amherst, Bedford, and Rockbridge Counties is superbly diverse. Voucher specimens document a vascular flora of 468 genera in 119 plant families with 963 taxa in the 3585-hectare research area. Largest collections of the Gorge flora are represented by the Asteraceae (130 spp.), Poaceae (93 spp.), Cyperaceae (61 spp.), Fabaceae (54 spp.), and Rosaceae (41 spp.). Of the species collected, 21% are introduced taxa. The collected taxa are compiled in an annotated list.
ABSTRACT New stations for 12 species of vascular plants considered rare, imperiled, or critically imperiled in Mississippi were discovered during collecting trips made from 1984-1989. The study area included two chalk outcrops and barrens, a mesic calcareous bluff, and a small stream bottom at the base of the bluffs along a transition area between the Pontotoc Ridge and Black Prairie physiographic regions for a distance of approximately 2.5 km. All sites are in Oktibbeha County, Mississippi, in the northeastern quarter of the state. The rare, imperiled, or critically imperiled species reported herein, which are usually associated with calcareous soils in Mississippi, are Apios priceana, Carex gracilescens, C. meadii, Carya laciniosa, Dodecatheon meadia, Euonymus atropurpureus, Fraxinus quadrangulata, Menispermum canadense, Nemastylis geminiflora, Panax quinquefolium, Penstemon tenuiflorus, and Swertia carolinien.
ABSTRACT The empress tree, Paulownia tomentosa (Thunb.) Steud., is native to eastern Asia and naturalized in portions of the eastern United States. In a central Virginia streamside forest, P. tomentosa trees ranged from 6 to 30 years in age (mean age = 17.1 years). The age distribution of P. tomentosa was unimodal with a strong peak in the 18 and 20 year age classes, demonstrating a major recruitment pulse in the early 1970s correlated with the passage of Hurricane Camille (August 1969). Paulownia tomentosa had the lowest importance value (=15.1) among the four dominant forest trees of the study area (Liriodendron tulipifera = 30.1, Betula lenta = 28.5, Platanus occidentalis = 16.0). Diameter distributions for all major tree species, except P. tomentosa, followed a concave pattern, which is representative of increasing or self-maintaining populations. The diameter and age distributions for P. tomentosa were convex, which indicates episodic establishment. Unlike many
Book Review: Genetics and Conservation of Rare Plants
ABSTRACT A 0.4 ha vegetation plot established in 1962 in Albright Grove, an old-growth cove forest in the Great Smoky Mountains, was resampled in 1992. A 0.6 ha plot encompassing the entire 1962 plot area was surveyed, mapped, and permanently marked in 1992. The diameter (dbh) and species of all live and dead tree stems >1.37 m tall were recorded in 10 0.04 ha contiguous plots in 1962, and in 60 0.01 ha contiguous subplots in 1992. Changes in the original 0.4 ha plot area over the 30-yr period are summarized here. The basal area of standing dead trees decreased from 15.7 to 3.5 m2/ha. Castanea dentata accounted for 29% of the original, and 0% of the recent standing dead basal area. Live tree basal area and biomass increased from 47.3 to 57.7 m2/ha, and 386 to 459 Mg/ha, respectively. Total stem density decreased from 642 to 563 stems/ha. Size-class